Design, synthesis, DNA binding, modeling, anticancer studies and DFT calculations of Schiff bases tethering benzothiazole-1,2,3-triazole conjugates

Exploring of N-phthalimide-linked 1,2,3-triazole analogues with promising -anti-SARS-CoV-2 activity: synthesis, biological screening, and molecular modelling studies

In this study, a library of phthalimide Schiff base linked to 1,4-disubstituted-1,2,3-triazoles was designed, synthesised, and characterised by different spectral analyses. All analogues have been introduced for in vitro assay of their antiviral activity against COVID-19 virus using Vero cell as incubator with different concentrations. The data revealed most of these derivatives showed potent cellular anti-COVID-19 activity and prevent viral growth by more than 90% at two different concentrations with no or weak cytotoxic effect on Vero cells. Furthermore, in vitro assay was done against this enzyme for all analogues and the results showed two of them have IC50 data by 90 µM inhibitory activity. An extensive molecular docking simulation was run to analyse their antiviral mechanism that found the proper non-covalent interaction within the Mpro protease enzyme. Finally, we profiled two reversible inhibitors, COOH and F substituted analogues that might be promising drug candidates for further development have been discovered.

In-silico design, pharmacophore-based screening, and molecular docking studies reveal that benzimidazole-1,2,3-triazole hybrids as novel EGFR inhibitors targeting lung cancer

Lung cancer is a complex and heterogeneous disease, which has been associated with various molecular alterations, including the overexpression and mutations of the epidermal growth factor receptor (EGFR). In this study, designed a library of 1843 benzimidazole-1,2,3-triazole hybrids and carried out pharmacophore-based screening to identify potential EGFR inhibitors. The 164 compounds were further evaluated using molecular docking and molecular dynamics simulations to understand the binding interactions between the compounds and the receptor. In-si-lico ADME and toxicity studies were also conducted to assess the drug-likeness and safety of the identified compounds. The results of this study indicate that benzimidazole-1,2,3-triazole hybrids BENZI-0660, BENZI-0125, BENZI-0279, BENZI-0415, BENZI-0437, and BENZI-1110 exhibit dock scores of -9.7, -9.6, -9.6, -9.6, -9.6, -9.6 while referencing molecule -7.9 kcal/mol for EGFR (PDB ID: 4HJO), respectively. The molecular docking and molecular dynamics simulations revealed that the identified compounds formed stable interactions with the active site of EGFR, indicating their potential as inhibitors. The in-silico ADME and toxicity studies showed that the compounds had favorable drug-likeness properties and low toxicity, further supporting their potential as therapeutic agents. Finally, performed DFT studies on the best-selected ligands to gain further insights into their electronic properties. The findings of this study provide important insights into the potential of benzimidazole-1,2,3-triazole hybrids as promising EGFR inhibitors for the treatment of lung cancer. This research opens up a new avenue for the discovery and development of potent and selective EGFR inhibitors for the treatment of lung cancer.Communicated by Ramaswamy H. Sarma.

Unveiling the anti-cancer potentiality of phthalimide-based Analogues targeting tubulin polymerization in MCF-7 cancerous Cells: Rational design, chemical Synthesis, and Biological-coupled Computational investigation

The present study deals with an anti-cancer investigation of an array of phthalimide-1,2,3-triazole molecular conjugates with various sulfonamide fragments against human breast MCF-7 and prostate PC3 cancer cell lines. The targeted 1,2,3-triazole derivatives 4a-l and 6a-c were synthesized from focused phthalimide-based alkyne precursors using a facile click synthesis approach and were thoroughly characterized using several spectroscopic techniques (IR, 1H, 13C NMR, and elemental analysis). The hybrid click adducts 4b, 4 h, and 6c displayed cytotoxic potency (IC50 values of 1.49, 1.07, and 0.56 μM, respectively) against MCF-7 cells. On the contrary, none of the synthesized compounds showed apparent cytotoxic efficacy for PC3 cells (IC50 ranging from 9.87- >100 μM). As a part of the mechanism analysis, compound 6c demonstrated a potent inhibitory effect (78.3 % inhibition) of tubulin polymerization in vitro with an IC50 value of 6.53 µM. In addition, biological assays showed that compound 6c could prompt apoptotic cell death and induce G2/M cell cycle arrest in MCF-7 cells. Accordingly, compound 6c can be further developed as an anti-breast cancer agent through apoptosis-induction.

Design, Synthesis, and Bioactivity Determination of Novel Malononitrile Derivatives Containing 1,2,3-Triazole

Using antifungal agrochemicals as the most economical solution might reduce plant diseases caused by pathogenic fungi, which have a significant negative impact on the quality and yield of food worldwide. In this work, 33 compounds (G) containing 1,2,3-triazole and malononitrile structures were synthesized. When the compounds were tested in vitro against six fungal species, they exhibited significant fungicidal activity toward Botrytis cinerea and Rhizoctonia solani. Compounds G17 and G30 displayed promising in vivo efficacy, with an EC50 of 0.19 and 0.27 mg/L respectively against R. solani. Fungal ergosterol production was suppressed by compounds G17 and G30, according to a preliminary analysis of their mechanism of action on R. solani using transcriptomics and scanning electron microscopy. It has been shown through experimentation that compounds G17 and G30 prevent R. solani from synthesizing ergosterol. Ultimately, it was anticipated that compounds G17 and G30 would be discovered to be low-toxic.

Design and synthesis of chromene-1,2,3-triazole benzene sulfonamide hybrids as potent carbonic anhydrase-IX inhibitors against prostate cancer

Considering the promising effects of molecular hybridization on drug discovery in recent years and the ongoing endeavors to develop bioactive scaffolds tethering the 1,2,3-triazole core, the present study sought to investigate whether the 1,2,3-triazole-linked chromene and benzene sulfonamide nucleus could exhibit activity against the human breast cancer cell line MCF-7 and prostate cancer cell line PC-3. To this end, three focused bioactive series of mono- and -bis-1,2,3-triazoles were effectively synthesized via copper-assisted cycloaddition of mono- and/or di-alkyne chromenone derivatives 2a and b and 9 with several sulfa drug azides 4a-d and 6. The resulting molecular derivatives were tested for cytotoxicity against prostate and breast cancer cells. Among the derivatives, 10a, 10c, and 10e exhibited potent cytotoxicity against PC-3 cells with IC50 values of 2.08, 7.57, and 5.52 μM compared to doxorubicin (IC50 = 2.31 μM) with potent inhibition of CA IX with IC50 values of 0.113, 0.134, and 0.214 μM. The most active compound, 10a, was tested for apoptosis-induction; it induced apoptosis by 31.9-fold cell cycle arrest at the G1-phase. Further, the molecular modeling approach highlighted the relevant binding affinity for the top-active compound 10a against CA IX as one of the most prominent PC-3 prostate cancer-associated biotargets.

Synthesis, Characterization, Antimicrobial and In Silico Studies of Isatin Schiff Base Linked 1,2,3-Triazole Hybrids

A new series of isatin-Schiff base linked 1,2,3-triazole hybrids has been synthesized using CuAAC approach from (E)-3-(phenylimino)-1-(prop-2-yn-1-yl)indolin-2-one derivatives in high yield (73-91 %). These synthesized derivatives were characterized using FT-IR, 1H NMR, 13C NMR, 2D-NMR and HRMS spectral techniques. The in vitro antimicrobial activity assay demonstrated that most of the tested hybrids exhibited promising activity. Compound 5 j displayed significant antibacterial efficacy against P. aeruginosa and B. subtilis with MIC value of 0.0062 μmol/mL. While, 5 j also showed better antifungal potency against A. niger with MIC value of 0.0123 μmol/mL. The docking studies of most promising compounds were performed with the well-known antibacterial and antifungal targets i. e. 1KZ1, 5TZ1. Molecular modelling investigations demonstrated that hybrids 5 h and 5 l exhibited good interactions with 1KZN and 5TZ1, with binding energies of -9.6 and -11.0 kcal/mol, respectively. Further, molecular dynamics studies of the compounds showing promising binding interactions were also carried out to study the stability of complexes of these hybrids with both the targets.

Design, synthesis, and unraveling the antibacterial and antibiofilm potential of 2-azidobenzothiazoles: insights from a comprehensive in vitro study

The present study reports the synthesis of 2-azidobenzothiazoles from substituted 2-aminobenzothiazoles using sodium nitrite and sodium azide under mild conditions. All the synthesized compounds were examined for their antibacterial activity against Gram (+) bacteria, Staphylococcus aureus (ATCC 25923), Enterococcus faecalis (ATCC 51299), Bacillus cereus (ATCC 10876) and Gram (-) bacteria, Escherichia coli (ATCC 10536), Pseudomonas aeruginosa (ATCC 10145), Klebsiella pneumonia (ATCC BAA-2146)and clinical isolates of Gram (+) Methicillin Resistant S. aureus (MRSA) and Multi Drug Resistant E. coli. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) values by broth dilution method revealed that compound 2d exhibited significant antibacterial potential against E. faecalis and S. aureus with MIC of 8 μg/mL, while other synthesized compounds had only moderate effects against all the tested species. The compound significantly inhibited the biofilm formation of the bacterial strains below its MIC. The selective cytotoxicity of Compound 2d towards bacterial cells was evidenced on extended exposure of Human Embryonic Kidney-293 cell line to higher concentrations of the compound. Hence, the present study confirmed that compound 2d can be a potential drug candidate for future development as an antibacterial drug.

Synthesis, Structural Investigations, DNA/BSA Interactions, Molecular Docking Studies, and Anticancer Activity of a New 1,4-Disubstituted 1,2,3-Triazole Derivative

We report herein a new 1,2,3-triazole derivative, namely, 4-((1-(3,4-dichlorophenyl)-1H-1,2,3-triazol-4-yl)methoxy)-2-hydroxybenzaldehyde, which was synthesized by copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC). The structure of the compound was analyzed using Fourier transform infrared spectroscopy (FTIR), 1H NMR, 13C NMR, UV-vis, and elemental analyses. Moreover, X-ray crystallography studies demonstrated that the compound adapted a monoclinic crystal system with the P21/c space group. The dominant interactions formed in the crystal packing were found to be hydrogen bonding and van der Waals interactions according to Hirshfeld surface (HS) analysis. The volume of the crystal voids and the percentage of free spaces in the unit cell were calculated as 152.10 Å3 and 9.80%, respectively. The evaluation of energy frameworks showed that stabilization of the compound was dominated by dispersion energy contributions. Both in vitro and in silico investigations on the DNA/bovine serum albumin (BSA) binding activity of the compound showed that the CT-DNA binding activity of the compound was mediated via intercalation and BSA binding activity was mediated via both polar and hydrophobic interactions. The anticancer activity of the compound was also tested by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay using human cell lines including MDA-MB-231, LNCaP, Caco-2, and HEK-293. The compound exhibited more cytotoxic activity than cisplatin and etoposide on Caco-2 cancer cell lines with an IC50 value of 16.63 ± 0.27 μM after 48 h. Annexin V suggests the induction of cell death by apoptosis. Compound 3 significantly increased the loss of mitochondrial membrane potential (MMP) levels in Caco-2 cells, and the reactive oxygen species (ROS) assay proved that compound 3 could induce apoptosis by ROS generation.

α-amylase inhibition and in silico studies of novel naphtho[2,3-d]imidazole-4,9-dione linked N-acyl hydrazones

Aim: To enrich the pool of α-amylase inhibitors to manage Type 2 diabetes. Methods: Synthesis, conformational study, α-amylase inhibitory action and various in silico studies of novel N'-(arylbenzylidene)-2-(4,9-dioxo-4,9-dihydro-1H-naphtho[2,3-d]imidazol-1-yl)acetohydrazides carried out. Results: Compound H6 demonstrated the highest activity (IC50 = 0.0437 μmol mL-1) among the tested compounds. Structure-activity relationship study suggested that variable substitution at the aryl ring has a pivotal role in determining the inhibitory action of tested compounds. Docking simulations of the most active compound (H6) confirmed its interaction potential with active site residues of A. oryzae α-amylase. The root-mean-square deviation fluctuations substantiated the stability of protein-ligand complex. Absorption, distribution, metabolism and excretion prediction revealed optimal values for absorption, distribution, metabolism and excretion parameters. Conclusion: The developed molecules could be beneficial for the development of novel α-amylase inhibitors to treat Type 2 diabetes.

Novel Bromo and methoxy substituted Schiff base complexes of Mn(II), Fe(III), and Cr(III) for anticancer, antimicrobial, docking, and ADMET studies

In this study, four new Mn(II), Fe(III), and Cr(III) complexes with two Schiff base ligands namely, 4-bromo-2-[(E)-{[4-(2-hydroxyethyl)phenyl]imino}methyl]phenol (HL1) and 2-[(E)-{[4-(2-hydroxyethyl)phenyl]imino}methyl]-4-methoxy phenol (HL2) have been synthesized and characterized. Different analytical and spectral methods have been used to characterize the ligands and their complexes. General formulas of [M(L)Cl2(H2O)2] for FeL1, CrL1 and CrL2, and [M(L)Cl(H2O)3] for MnL2 were proposed. HOMO and LUMO energies, as well as the electrical characteristics, have been calculated using DFT/B3LYP calculations with Gaussian 09 program. The optimized lowest energy configurations of the complexes are proven. The disc diffusion technique was used to test the pharmacological activities' antibacterial efficacy against diverse bacterial and fungus species. The MTT technique was used to assess the in vitro cytotoxicity of the ligands and their metal complexes on the Hep-G2 human liver carcinoma cell line and the MCF-7 human breast cancer cell line. All compounds displayed better activity compared to the free ligands. MnL2 complex showed predominant activity when compared to the other complexes with an IC50 value of 2.6 ± 0.11 μg/ml against Hep-G2, and against MCF-7 the IC50 value was 3.0 ± 0.2 μg/ml which is less than the standard drug cisplatin (4.0 μg/ml). UV-vis electronic spectrum and gel electrophoresis techniques have been used to investigate the compounds' affinity to bind and cleavage CT-DNA. The interaction's binding constants, or Kb, have been identified, and it was discovered that the new complexes' binding affinities are in the order of FeL1 > MnL2 > CrL2 > CrL1, and the binding mechanism has been suggested. To assess the kind of binding and binding affinity of the investigated drugs with human DNA, a molecular docking study was carried out (PDB:1bna). The acquired results supported the intercalation binding mechanism proposed in the experimental part and revealed that complexes may be inserted into the DNA molecule to stop DNA replication. According to ADMET data, the synthesized compounds have a high bioavailability profile and their physicochemical and pharmacological features remained within Lipinski's RO5 predicted limitations.

Synthesis and pesticidal activity of new 1,3,4-oxadiazole thioether compounds containing a trifluoromethylpyrazoyl moiety

In order to find new lead compounds with high pesticidal activity, a series of 1,3,4-oxadiazole thioether compounds (5 series) were designed by using penthiopyrad as a synthon. They were synthesized easily via five steps by using ethyl 4,4,4-trifluoro-3-oxobutanoate and triethyl orthoformate as starting materials. The synthesized compounds were characterized by ¹H NMR, ¹³C NMR and HRMS. The compound 2-(benzylthio)-5-(1-methyl-3-(trifluoromethyl)-1H-pyrazol-4-yl)-1,3,4-oxadiazole (5a) was further determined by X-ray single-crystal diffraction. It crystallized in the monoclinic system, space group P2₁/c, Z = 4. All the 1,3,4-oxadiazole thioether derivatives were screened for fungicidal activity against ten fungi and herbicidal activity against two weeds. The bioassay results indicated that some of the synthesized 1,3,4-oxadiazole compounds exhibited good fungicidal activity (> 50% inhibition) against the plant pathogens Sclerotinia sclerotiorum and Rhizoctonia solani at 50 μg/mL. Some of them exhibited certain herbicidal activity, and compounds 2-((3-chlorobenzyl)thio)-5-(1-methyl-3-(trifluoromethyl)-1H-pyrazol-4-yl)-1,3,4-oxadiazole (5e) and 2-((4-bromobenzyl)thio)-5-(1-methyl-3-(trifluoromethyl)-1H-pyrazol-4-yl)-1,3,4-oxadiazole (5 g) had bleach effect. Molecular docking is to find the best fit orientation of the 2-((4-bromobenzyl)thio)-5-(1-methyl-3-(trifluoromethyl)-1H-pyrazol-4-yl)-1,3,4-oxadiazole (5 g) molecule with the SDH protein (PDB: 2FBW). The docking results indicate that the compound 5 g and the lead compound penthiopyrad have similar binding interactions with SDH and carbonyl is a key group for these compounds.

Design and Synthesis of Benzene Homologues Tethered with 1,2,4-Triazole and 1,3,4-Thiadiazole Motifs Revealing Dual MCF-7/HepG2 Cytotoxic Activity with Prominent Selectivity via Histone Demethylase LSD1 Inhibitory Effect

In this study, an efficient multistep synthesis of novel aromatic tricyclic hybrids incorporating different biological active moieties, such as 1,3,4-thiadiazole and 1,2,4-triazole, was reported. These target scaffolds are characterized by having terminal lipophilic or hydrophilic parts, and their structures are confirmed by different spectroscopic methods. Further, the cytotoxic activities of the newly synthesized compounds were evaluated using in vitro MTT cytotoxicity screening assay against three different cell lines, including HepG-2, MCF-7, and HCT-116, compared with the reference drug Taxol. The results showed variable performance against cancer cell lines, exhibiting MCF-7 and HepG-2 selectivities by active analogs. Among these derivatives, 1,2,4-triazoles 11 and 13 and 1,3,4-thiadiazole 18 were found to be the most potent compounds against MCF-7 and HepG-2 cancer cells. Moreover, structure–activity relationship (SAR) studies led to the identification of some potent LSD1 inhibitors. The tested compounds showed good LSD1 inhibitory activities, with an IC₅₀ range of 0.04–1.5 μM. Compounds 27, 23, and 22 were found to be the most active analogs with IC₅₀ values of 0.046, 0.065, and 0.074 μM, respectively. In addition, they exhibited prominent selectivity against a MAO target with apparent cancer cell apoptosis, resulting in DNA fragmentation. This research provides some new aromatic-centered 1,2,4-triazole-3-thione and 1,3,4-thiadiazole analogs as highly effective anticancer agents with good LSD1 target selectivity.

Design, Synthesis and Molecular Docking of Novel Acetophenone-1,2,3-Triazoles Containing Compounds as Potent Enoyl-Acyl Carrier Protein Reductase (InhA) Inhibitors

New medications are desperately needed to combat rising drug resistance among tuberculosis (TB) patients. New agents should ideally work through unique targets to avoid being hampered by preexisting clinical resistance to existing treatments. The enoyl-acyl carrier protein reductase InhA of M. tuberculosis is one of the most crucial targets since it is a promising target that has undergone extensive research for anti-tuberculosis drug development. A well-known scaffold for a variety of biological activities, including antitubercular activity, is the molecular linkage of a1,2,3-triazole with an acetamide group. As a result, in the current study, which was aided by ligand-based molecular modeling investigations, 1,2,3-triazolesweredesigned and synthesized adopting the CuAAC aided cycloaddition of 1-(4-(prop-2-yn-1-yloxy)phenyl)ethanone with appropriate acetamide azides. Standard spectroscopic methods were used to characterize the newly synthesized compounds. In vitro testing of the proposed compounds against the InhA enzyme was performed. All the synthesized inhibitors completely inhibited the InhA enzyme at a concentration of 10 µM that exceeded Rifampicin in terms of activity. Compounds 9, 10, and 14 were the most promising InhA inhibitors, with IC₅₀ values of 0.005, 0.008, and 0.002 µM, respectively. To promote antitubercular action and investigate the binding manner of the screened compounds with the target InhA enzyme’s binding site, a molecular docking study was conducted.

Novel Hybrid 1,2,4- and 1,2,3-Triazoles Targeting Mycobacterium Tuberculosis Enoyl Acyl Carrier Protein Reductase (InhA): Design, Synthesis, and Molecular Docking

Tuberculosis (TB) caused by Mycobacterium tuberculosis is still a serious public health concern around the world. More treatment strategies or more specific molecular targets have been sought by researchers. One of the most important targets is M. tuberculosis' enoyl-acyl carrier protein reductase InhA which is considered a promising, well-studied target for anti-tuberculosis medication development. Our team has made it a goal to find new lead structures that could be useful in the creation of new antitubercular drugs. In this study, a new class of 1,2,3- and 1,2,4-triazole hybrid compounds was prepared. Click synthesis was used to afford 1,2,3-triazoles scaffold linked to 1,2,4-triazole by fixable mercaptomethylene linker. The new prepared compounds have been characterized by different spectroscopic tools. The designed compounds were tested in vitro against the InhA enzyme. At 10 nM, the inhibitors 5b, 5c, 7c, 7d, 7e, and 7f successfully and totally (100%) inhibited the InhA enzyme. The IC50 values were calculated using different concentrations. With IC50 values of 0.074 and 0.13 nM, 7c and 7e were the most promising InhA inhibitors. Furthermore, a molecular docking investigation was carried out to support antitubercular activity as well as to analyze the binding manner of the screened compounds with the target InhA enzyme's binding site.

Synthesis, Characterization and Nanoformulation of Novel Sulfonamide-1,2,3-triazole Molecular Conjugates as Potent Antiparasitic Agents

Toxoplasma gondii (T. gondii) is a highly prevalent parasite that has no gold standard treatment due to the poor action or the numerous side effects. Focused sulfonamide-1,2,3-triazole hybrids 3a–c were wisely designed and synthesized via copper catalyzed 1,3-dipolar cycloaddition approach between prop-2-yn-1-alcohol 1 and sulfa drug azides 2a–c. The newly synthesized click products were fully characterized using different spectroscopic experiments and were loaded onto chitosan nanoparticles to form novel nanoformulations for further anti-Toxoplasma investigation. The current study proved the anti-Toxoplasma effectiveness of all examined compounds in experimentally infected mice. Relative to sulfadiazine, the synthesized sulfonamide-1,2,3-triazole (3c) nanoformulae demonstrated the most promising result for toxoplasmosis treatment as it resulted in 100% survival, 100% parasite reduction along with the remarkable histopathological improvement in all the studied organs.

Synthesis and Antimicrobial, Anticancer and Anti-Oxidant Activities of Novel 2,3-Dihydropyrido[2,3-d]pyrimidine-4-one and Pyrrolo[2,1-b][1,3]benzothiazole Derivatives via Microwave-Assisted Synthesis

In our attempt towards the synthesis and development of effective antimicrobial, anticancer and antioxidant agents, a novel series of 2,3-dihydropyrido[2,3-d]pyrimidin-4-one 7a–e and pyrrolo[2,1-b][1,3]benzothiazoles 9a–e were synthesized. The synthesis of 2-(1,3-benzo thiazol-2-yl)-3-(aryl)prop-2-enenitrile (5a–e) as the key intermediate was accomplished by a microwave efficient method. Via a new variety oriented synthetic microwave pathway, these highly functionalized building blocks allowed access to numerous fused heteroaromatic such as 7-amino-6-(1,3-benzo thiazol-2-yl)-5-(aryl)-2-thioxo-2,3dihydropyrido [2,3-d]pyrimidin-4(1H)-one 7a–e and 1-amino-2-(aryl)pyrrolo[2,1-b][1,3]benzothiazole-3-carbonitrile derivatives 9a–e in order to study their antimicrobial and anticancer activity. The present investigation offers effective and rapid new procedures for the synthesis of the newly polycondensed heterocyclic ring systems. All the newly synthesized compounds were evaluated for antimicrobial, anticancer and antioxidant activity. Compounds 7a,d, and 9a,d showed higher antimicrobial activity than cefotaxime and fluconazole while the remaining compounds exhibited good to moderate activity against bacteria and fungi. An anticancer evaluation of the newly synthesized compounds against the three tumor cell lines (lung cell NCI-H460, liver cancer HepG2 and colon cancer HCT-116) exhibited that compounds 7a, d, and 9a,d have higher cytotoxicity against the three human cell lines compared to doxorubicin as a reference drug. These compounds also exhibited higher antioxidant activity and a great ability to protect DNA from damage induced by bleomycin.

Halting Tumor Progression via Novel Non-Hydroxamate Triazole-Based Mannich Bases MMP-2/9 Inhibitors; Design, Microwave-Assisted Synthesis, and Biological Evaluation

Matrix metalloproteinases (MMPs) are key signaling modulators in the tumor microenvironment. Among MMPs, MMP-2 and MMP-9 are receiving renewed interest as validated druggable targets for halting different tumor progression events. Over the last decades, a diverse range of MMP-2/9 inhibitors has been identified starting from the early hydroxamic acid-based peptidomimetics to the next generation non-hydroxamates. Herein, focused 1,2,4-triazole-1,2,3-triazole molecular hybrids with varying lengths and decorations, mimicking the thematic features of non-hydroxamate inhibitors, were designed and synthesized using efficient protocols and were alkylated with pharmacophoric amines to develop new Mannich bases. After full spectroscopic characterization the newly synthesized triazoles tethering Mannich bases were subjected to safety assessment via MTT assay against normal human fibroblasts, then evaluated for their potential anticancer activities against colon (Caco-2) and breast (MDA-MB 231) cancers. The relatively lengthy bis-Mannich bases 15 and 16 were safer and more potent than 5-fluorouracil with sub-micromolar IC₅₀ and promising selectivity to the screened cancer cell lines rather than normal cells. Both compounds upregulated p53 (2–5.6-fold) and suppressed cyclin D expression (0.8–0.2-fold) in the studied cancers, and thus, induced apoptosis. 15 was superior to 16 in terms of cytotoxic activities, p53 induction, and cyclin D suppression. Mechanistically, both were efficient MMP-2/9 inhibitors with comparable potencies to the reference prototype hydroxamate-based MMP inhibitor NNGH at their anticancer IC₅₀ concentrations. 15 (IC₅₀ = 0.143 µM) was 4-fold more potent than NNGH against MMP-9 with promising selectivity (3.27-fold) over MMP-2, whereas 16 was comparable to NNGH. Concerning MMP-2, 16 (IC₅₀ = 0.376 µM) was 1.2-fold more active than 15. Docking simulations predicted their possible binding modes and highlighted the possible structural determinants of MMP-2/9 inhibitory activities. Computational prediction of their physicochemical properties, ADMET, and drug-likeness metrics revealed acceptable drug-like criteria.

New 1,2,3-Triazole Scaffold Schiff Bases as Potential Anti-COVID-19: Design, Synthesis, DFT-Molecular Docking, and Cytotoxicity Aspects

Schiff bases encompassing a 1,2,3-triazole motif were synthesized using an efficient multi-step synthesis. The formations of targeted Schiff base ligands were confirmed by different spectroscopic techniques (FT-IR, ¹H NMR, ¹³C NMR, and CHN analysis). The spectral data analysis revealed that the newly designed hydrazones exist as a mixture of trans-E and cis-E diastereomers. Densityfunctional theory calculations (DFT) for the Schiff bases showed that the trans-trans form has the lowest energy structure with maximum stability compared to the other possible geometrical isomers that could be present due to the orientation of the amidic NH-C=O group. The energy differences between the trans-trans on one side and syn-syn and syn-trans isomers on the other side were 9.26 and 5.56 kcal/mol, respectively. A quantitative structure-activity relationship investigation was also performed in terms of density functional theory. The binding affinities of the newly synthesized bases are, maybe, attributed to the presence of hydrogen bonds together with many hydrophobic interactions between the ligands and the active amino acid residue of the receptor. The superposition of the inhibitor N3 and an example ligand into the binding pocket of 7BQY is also presented. Further interesting comparative docking analyses were performed. Quantitative structure-activity relationship calculations are presented, illustrating possible inhibitory activity. Further computer-aided cytotoxicity analysis by Drug2Way and PASS online software was carried out for Schiff base ligands against various cancer cell lines. Overall, the results of this study suggest that these Schiff base derivatives may be considered for further investigation as possible therapeutic agents for COVID-19.

Preparation and DFT Study for New Three-Ring Supramolecular H-Bonded Induced Liquid Crystal Complexes

Supramolecular three-ring Schiff base novel liquid crystal complexes have been prepared and investigated. Schiff bases of para-substituted aniline derivatives and para-pyridine carbaldehyde have been prepared and then mixed in equimolar quantities with para-alkoxy benzoic acids. On one side, the alkoxy chain length varies from 8 to 16 carbon atoms. On the other side, terminal small compact groups substituting aniline with various polarities are used. Hydrogen-bonding interaction was elucidated by FTIR spectroscopy. The mesomorphic thermal and optical characteristics of the samples were obtained by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). All samples exhibit enantiotropic mesophases. Experimental results obtained for the induced mesophases were correlated with density functional theory (DFT) theoretical calculations. The results revealed that both the polar compact groups' polarity and the alkoxy chain lengths contribute strongly to mesomorphic characteristics and thermal stabilities of the mesophases. Surprisingly, the observed values of enthalpy changes associated with the crystalline mesomorphic transitions lie in the range of 2.2-12.5 kJ/mol. However, the enthalpy changes corresponding to the mesomorphic-isotropic transitions vary from 0.9 to 13.9 kJ/mol, depending on the polarity of para-attached groups to the aniline moiety.

New Liquid Crystal Assemblies Based on Cyano-Hydrogen Bonding Interactions

A new selection of supramolecular liquid crystal complexes based on complementary molecules formed via hydrogen-bonding interactions is reported. All prepared complexes were prepared from 4-n-alkoxybenzoic acid (An) and N-4-cyanobenzylidene-4-n-(hexyloxy)benzenamine (I). FT-IR, temperature gradient NMR, Mass Spectrometer and Chromatography spectroscopy were carried out to confirm the -CN and -COOH H-bonded complexation by observing their Fermi-bands and the effects of the 1H-NMR signals as well as its elution signal from HPLC. Moreover, binary phase diagrams were established for further confirmation. All formed complexes (I/An) were studied by the use of differential scanning calorimetry and their phase properties were validated through the use of polarized optical microscopy Results of mesomorphic characterization revealed that all presented complexes exhibited enantiotropic mesophases and their type was dependent on the terminal lengths of alkoxy chains. Also, the mesomorphic temperature ranges decreased in the order I/A6 > I/A8 > I/A10 > I/A16 with linear dependency on the chain length. Finally, the density functional theory computational modeling has been carried out to explain the experimental findings. The relation between the dimensional parameters was established to show the effect of the aspect ratio on the mesophase range and stability. The normalized entropy of the clearing transitions (∆S/R) was calculated to illustrate the molecular interaction enhancements with the chain lengths.

Novel 2-Hydroselenonicotinonitriles and Selenopheno[2, 3-b]pyridines: Efficient Synthesis, Molecular Docking-DFT Modeling, and Antimicrobial Assessment

Selenium containing heterocyclic compounds gained great interest as bioactive molecules as of late. This report explores the design, synthesis, characterization, and antimicrobial screening of new pyridine derivatives endowed with selenium moieties. A one-pot multicomponent system with a solvent-free, microwave irradiation environment was employed to afford this series. The spectroscopic techniques were exploited to verify the structures of the synthesized derivatives. Additionally, the agar diffusion method was employed to determine the antimicrobial activity of all the desired compounds. Of all the synthesized molecules, 9b, 12b, 14f, and 16d exhibited well to remarkable antibacterial and antifungal activities. Moreover, derivative 14f demonstrated the most potent antibacterial and antifungal performance. The results were also supported by molecular docking studies, utilizing the MOE (molecular operating environment) which revealed the best binding mode with the highest energy interaction within the binding pocket. Lastly, theoretical DFT calculations were carried out in a gas phase at B3LYP 6-311G (d,p) basis set to predict the molecular geometries and chemical reactivity descriptors. DFT results have been used to illustrate that molecular docking findings and biological activity assessments.

Design of molecular hybrids of phthalimide-triazole agents with potent selective MCF-7/HepG2 cytotoxicity: Synthesis, EGFR inhibitory effect, and metabolic stability

This study reports an efficient and convenient click chemistry synthesis of a novel series of phthalimide scaffold linked to 1,2,3 triazole ring and terminal lipophilic fragments. Structures of newly synthesized compounds were well characterized by different spectroscopic tools. In vitro MTT cytotoxicity assay was performed comparing the cytotoxic effects of newly synthesized compounds to staurosporine using three different types: human liver cancer cell line (HepG2), Michigan cancer foundation-7 (MCF-7) and human colorectal carcinoma cell line (HCT116). The initial screening showed excellent to moderate anticancer activity for these newly synthesized compounds with high degree of cell line selectivity with micromolar (µM) half maximal inhibitory concentration (IC₅₀) values against tumor cells. The SAR analysis of these derivatives confirmed the role of molecular fragments including phthalimide, linker, triazole, and terminal tails in correlation to activity. In addition, enzymatic inhibitory assay against wild type EGFR was performed for the most active compounds to get more details about their mechanism of action. In order to further explore their binding affinities, molecular docking simulation was studied against EGFR site. The results obtained from molecular docking study and those obtained from cytotoxic screening were correlated. One of the most prominent analogs is (6f) with terminal disubstituted ring and amide linker showed selective MCF-7 cytotoxicity profile with IC₅₀ 0.22 µM and 79 nM to EGFR target. Extensive structure activity relationship (SAR) analyses were also carried out. The pharmacokinetic profile of (6f) was studied showing good metabolic stability and long duration behavior. This design offered a potent selective anticancer phthalimide-triazole leads for further optimization in cancer drug discovery.

Novel 1,2,3-triazole-tethered Pam3CAG conjugates as potential TLR-2 agonistic vaccine adjuvants

A focused library of water soluble 1,2,3-triazole tethered glycopeptide conjugates derived from variety of azido-monosaccharides and aliphatic azido-alcohols were synthesized through manipulation at the C-terminus of Pam₃CAG and screened for their potential as TLR2 agonistic adjuvants against HBsAg antigen. In vitro ligand induced TLR2 signal activation was observed with all the analogues upon treatment with HEK blue TLR2 cell lines. Conjugate derived from ribose (6e), which exhibited pronounced HBsAg specific antibody (IgG) titer also shown enhanced CD8+ population indicating superior cell mediated immunity compared to standard adjuvant Pam₃CSK₄. Further, docking studies revealed ligand induced heterodimerization between TLR1 and 2. Overall, the result indicates the usefulness of novel conjugates as potential vaccine adjuvant.

A New Family of Benzo[h]Chromene Based Azo Dye: Synthesis, In-Silico and DFT Studies with In Vitro Antimicrobial and Antiproliferative Assessment

The high biological activity of the chromene compounds coupled with the intriguing optical features of azo chromophores prompted our desire to construct novel derivatives of chromene incorporating azo moieties 4a-l, which have been prepared via a three-component reaction of 1-naphthalenol-4-[(4-ethoxyphenyl) azo], 1, with the benzaldehyde derivatives and malononitrile. The structural identities of the azo-chromene 4a-l were confirmed on the basis of their spectral data and elemental analysis, and a UV-visible study was performed in a Dimethylformamide (DMF) solution for these molecules. Additionally, the antimicrobial activity was investigated against four human pathogens (Gram-positive and Gram-negative bacteria) and four fungi, employing an agar well diffusion method, with their minimum inhibitory concentrations being reported. Molecules 4a, 4g, and 4h were discovered to be more efficacious against Syncephalastrum racemosum (RCMB 05922) in comparison to the reference drugs, while compounds 4b and 4h demonstrated the highest inhibitory activity against Escherichia coli (E. coli) in evaluation against the reference drugs. Moreover, their cytotoxicity was assessed against three different human cell lines, including human colon carcinoma (HCT-116), human hepatocellular carcinoma (HepG-2), and human breast adenocarcinoma (MCF-7) with a selection of molecules illustrating potency against the HCT-116 and MCF-7 cell lines. Furthermore, the molecular modeling results depicted the binding interactions of the synthesized compounds 3b and 3h in the active site of the E. coli DNA gyrase B enzyme with a clear SAR (structure-activity relationship) analysis. Lastly, the density functional theory's (DFTs) theoretical calculations were performed to quantify the energy levels of the Frontier Molecular Orbitals (FMOs) and their energy gaps, dipole moments, and molecular electrostatic potentials. These data were utilized in the chemical descriptor estimations to confirm the biological activity.